Here's where I start asking questions trying to figure out why you want to upgrade and you're going to interpret my investigation as though I'm being a disc. In reality, I'm just trying to figure out if you really want/need to upgrade or if you are just buying shiz because other people told you you should and you feel compelled to do it.

So, why do you want to upgrade your wheels in the first place? If it's because you want lighter wheels, then why do you want lighter wheels? If you want lighter wheels because they are faster, then why do you want to go faster? If you want to go faster because you are racing, then the reasons to get lighter wheels and tubeless tires for racing are different than the reasons why you should get lighter wheels and tubeless tires for recreational riding.

Why do you mountain bike in the first place? If it's because you like to get some exercise in the outdoors, then what you have is fine.

Lighter wheels and tubeless tires may not be the answer to whatever problem you have (real or perceived). Let me know what problem or defiency you are facing and I will help you find an appropriate and cost effective solution.

Please, please, please DO NOT buy stuff because other people make you feel bad for not having it.

No, YOU don't understand. You're making an ass of yourself for all of eternity.

Here's where I start asking questions trying to figure out why you want to upgrade and you're going to interpret my investigation as though I'm being a disc. In reality, I'm just trying to figure out if you really want/need to upgrade or if you are just buying shiz because other people told you you should and you feel compelled to do it.

So, why do you want to upgrade your wheels in the first place? If it's because you want lighter wheels, then why do you want lighter wheels? If you want lighter wheels because they are faster, then why do you want to go faster? If you want to go faster because you are racing, then the reasons to get lighter wheels and tubeless tires for racing are different than the reasons why you should get lighter wheels and tubeless tires for recreational riding.

Why do you mountain bike in the first place? If it's because you like to get some exercise in the outdoors, then what you have is fine.

Lighter wheels and tubeless tires may not be the answer to whatever problem you have (real or perceived). Let me know what problem or defiency you are facing and I will help you find an appropriate and cost effective solution.

Please, please, please DO NOT buy stuff because other people make you feel bad for not having it.

Nope, I'm not buying stuff because other people are telling me to. I'm upgrading my entry level drive train and are looking at new wheels as my current set have an 8 speed flywheel and I'm going to be running a 10 speed setup. I have the option to get tubed or tubeless rims.

I bike to get outside, be active and see new things. I like the idea of entering races, but I'm not there yet.

While you may not get as many pinch flats with tubeless, you would still need to carry a tube and/or boot in case of sidewall cut. Many ppl go tubeless for low pressures. This will increase the chance of burping and may even deplete your tire of air instantly. This could also happen with a pinch flat, but, might not be as quickly as burping the bead.

I already ride around at about 27-31lbs with tubes. I can ride tubes around 25lbs (i'm 165lbs geared up). I don't like the squirm you get from pressure that low. Whether burping or pinch flatting, i don't like banging my rims on rocks. 28ish pounds solves this and tubes work for this pressure. I've pinch flatted twice in the past year and a half. One was because i decided to slam my rear wheel into a curb. This bent my rim and probably would have flatted either way.

I seem to change tires often depending on the terrain i'm going to ride or simply because i feel like i want more or less knobs on a ride. Setting up tubeless each time would seem to be annoying for this.

UST wheels and tires would be the only way i would go tubeless. I don't feel safe with a rigged setup. Unfortunately, not enough UST tire models to select from to make the switch.

The reason to run tubless two fold.
1) Lower pressures that should give you better grip (run too low on tubes an get pinch flats)
2) Less risk of thorn flats with sealant.

weight is about a wash and tubless is much harder to set-up.

I run tubes in the Az desert in the last 600 miles of riding I have had 1 pinch flat. This is with plenty of rocks on the trail. I typically run 30-35 psi and I am 160lbs fully suited up and I pinch flatted due to starting the ride too low on pressure. (25 psi or lower). I have had many thorn flats, but I have only had to change a tire 3 times on the trail due to flats. 1 for the pinch flat and 2 for thorn flats. Most of the time when cactus causes flats it is a slow leak I fixed after the ride at home. Changing a tube is easy and I can buy them in bulk for $5.00 each or less and can patch them for a $1.00.

This beats dealing with stans and other sealants that dry out cause problems. Plus I reminded of the guy on a 29er that I met 4 miles from the trail head. He had a flat rear tire when is tubeless popped off the rim. I had a pump, but no CO2 and the pump was not able to "seat" the bead. I carry only 1 spare 26" tube and had another 16 miles to ride so I just had to leave him.

I run tubeless and love it. I also carry a tube and co2. With lower pressure I spin out less on technical rock climbs, ride is smoother, less fatigue, no flats. Set up was easy. I run UST with regular tires and Stan's sealant. Best set up decision I've made so far.

No, YOU don't understand. You're making an ass of yourself for all of eternity.

I bike to get outside, be active and see new things. I like the idea of entering races, but I'm not there yet.

you're already going from 8speed to 10speed for reasons that make sense only to you. why ask us about tubeless?

sounds like you are a guy with some money to spend who likes to have nice stuff, even if he doesn't necessarily know why. all the guys like you have tubeless. all of them say it is way superior to tubes, even though they can't exactly explain why.

it sounds like other people do all the work on your bike, so that is something in favor of getting tubeless - if you don't have to do the work yourself and have the money, why not get it?

i hope it doesn't sound like i'm raining on your parade. i guess i'm just saying that only you can decide, and a lot of guys like you have gone to tubeless. whichever way you go, i hope you are happy and get to ride it plenty.

I run in AZ also. I went tubeless conversion on my GT and never looked back. The reason was too many thorn punctures. I like to wake up in the morning and ride and not have to worry about changing/repairing a flat before my ride. My new Salsa has MTB tubeless wheels and just pulled the tubes out the other day and went tubeless. Mush easier to go tubeless if you have tubeless rims.
The tubeless works fine for me and geared up I'm at 245-250.
I also run between 20 and 30 lbs. Depends on where I'm riding.
I also still carry a tube with me just in case.

Only had one thorn flat (sidewall) so far since September. That's one of the reasons I went tubless. No flats, no burps so far, but I do run a little higher pressure (about 38-42) psi. I ride light so the wife is the spare tire - helps if you live a couple miles off the trail head and you know help is less than 5 minutes away via cell phone.

- Going tubeless has reduced flats of any kind to zero for me. Not just the pinch ones, but all.
- I have not experienced burping even at low pressures.*
- Even if the weight remains the same, liquid sealant doesn't affect acceleration as much as a solid tube. And usually the weight is a bit lower when you go tubeless.
- I noticed a decrease in rolling resistance. I'm not a racer, but I simply enjoy the ride more when I can make the bike move more fluidly.

* Instead of a pressure thing, I'm convinced it's more a question of a compatible rim and tire. Mine are Stan's Crests with yellow tape and Schwalbe Nobby Nics. Also, I think difficulty setting up to run tubeless stems from incompatible parts or incorrect procedure. I did as all the how-tos told me and have had zero problems.

I run in AZ also. I went tubeless conversion on my GT and never looked back. The reason was too many thorn punctures. I like to wake up in the morning and ride and not have to worry about changing/repairing a flat before my ride. My new Salsa has MTB tubeless wheels and just pulled the tubes out the other day and went tubeless. Mush easier to go tubeless if you have tubeless rims.
The tubeless works fine for me and geared up I'm at 245-250.
I also run between 20 and 30 lbs. Depends on where I'm riding.
I also still carry a tube with me just in case.

Same thing here, except I converted using rimstrips on a marlin, even though I was told you couldn't do it-I proved everyone wrong on that one. I got tired of having to air up my tubed tires for every stinking ride the next morning, I had 1 flat a day with tubes, even ran out of patches. I weigh as much as you do all geared up, and my trail rides are cushy and loose terrain here is no challenge. I worked hard to get the rear tire on it aint coming off without being forced. I havent even burped on my setup and I purposely try to run over cactus thorns and mesquite thorns but have yet to get one stuck where the sealant had to do its job. I carry a tube & Co2.

I have had only one flat in 1200 miles of running tubeless. A sidewall cut, and that would have sealed had I kept a closer eye on the amount of sealent in the tire. And actually, I was able to ride most of the way back before it got too soft to ride. I burped some air when falling off a log, but it sealed up again and I was able to ride out. The usual greenbriar thorns that cause most flats around here are a non-issue. I don't carry any flat repair equipment, but where I ride it is a few miles walk at the most to get to a road.

Weight savings is about 60 grams per wheel -- a cheap way to save weight where it matters most. Some people claim that there is energy savings because of lessened friction between the tube and tire. Indeed, cars with tubeless tires do get better mileage. I can tell the difference riding tubeless, but I think it is more weght savings than anything.

It took some learning before I would call tubeless "convenient". A different skill set is required than dealing with tubes, but with proper equipment and technique, it is easier IMO. There is certainly no danger of pinching a tube while mounting. I do think the tire holds air longer than with tubes.

I run 25 PSI rear & 20 front, and it is more comfortable and handles better than 30 & 25 that I ran with tubes. No instability that people mention. I start seeing that at around 15 PSI.

Hate to thread-jack, but will tubeless systems prevent goathead flats? Darn things are worse than thumbtacks...I'm considering tubeless to avoid changing tubes all the time, but I don't like the idea that you can deflate the tire at low pressures just by hitting a rock wrong. Tubes with gel sound better...or tire strips.

Stan's has worked well for me vs. goatheads. I have some S-Works Fast Traks w/ really thin casings that are full of goathead holes. Every once in a while, a 'plug' of sealant will knock loose, and I have to shake the bike for a few seconds, then orient the hole downward for a bit, and let it reseal. That may seem like a lot, but it's way easier than reinstalling a new tube. Barely any pressure loss.

1. went back to marked spot on top of hill (pavement)
2. rolled down hill without touching brakes
3. marked spot on flat at bottom that bike came to rest.
4. Repeat process 5 times (to get a slight range)

I still tried tubeless for part of the season - again, no real weight savings. True, I did not pinch flat (which I wasnt really doing with tubes) but I did tear a sidewall once causing the stans jizz to fly everywhere.

Fortunately I had a spare tube, but it back in and have not bothered going tubless again.

Best I can see is tubeless is just a preference. Sorta like schrader valve VS presta valve. But thats another topic......

Here's where I start asking questions trying to figure out why you want to upgrade and you're going to interpret my investigation as though I'm being a disc. In reality, I'm just trying to figure out if you really want/need to upgrade or if you are just buying shiz because other people told you you should and you feel compelled to do it.

So, why do you want to upgrade your wheels in the first place? If it's because you want lighter wheels, then why do you want lighter wheels? If you want lighter wheels because they are faster, then why do you want to go faster? If you want to go faster because you are racing, then the reasons to get lighter wheels and tubeless tires for racing are different than the reasons why you should get lighter wheels and tubeless tires for recreational riding.

Why do you mountain bike in the first place? If it's because you like to get some exercise in the outdoors, then what you have is fine.

Lighter wheels and tubeless tires may not be the answer to whatever problem you have (real or perceived). Let me know what problem or defiency you are facing and I will help you find an appropriate and cost effective solution.

Please, please, please DO NOT buy stuff because other people make you feel bad for not having it.

006_007, your test sounds scientific enough to me. You confirm my belief that it is unlikely that rolling resistance due to tire/tube interaction is significant or occurs at all. BUT, if you tried the same test at say 30 back /25 front PSI with tubes and 25/20 without, over some roots and other uneven trail surfaces, I would expect to see an improvment. The tire conforms to the trail surface rather than bouncing over it. There is a whitepaper by Schwalbe where they tested this, and my seat-of-the-pants experience agrees. I also believe that the tires get better traction. It is definately more comfortable!

As for weight savings, Stans recommends 4 ounces of goo per tire for 29" 2.2s. You will not realize any weight savings using that much. Stan's main point of marketing seems to be puncture resistance as the video shows.

But for those of us who do not repeatedly ride over nail beds, you do not need that much. If the bead is sealed, just having the inner surface of the tire wet with the stuff will protect from greenbrier punctures. I run between one and two ounces. As long as there is a pool of it in the tire, you are good.

Originally Posted by CSC

but I don't like the idea that you can deflate the tire at low pressures just by hitting a rock wrong. Tubes with gel sound better...or tire strips.

We don't have many rocks around here, but from what I hear it's really not a big issue. When I burped mine, it may well have shredded the tube if I had had one. Nothing is foolproof.

If you are leery of lower pressure, you can run tubeless at the same pressure you are using now. If sealant is called on to prevent a flat, from everything I have read, it works better with a tubeless setup than in a tube.

I'm looking for ways to make my bike lighter, will going tubeless help?

Some details, if you want them:

I've been riding this bike (2011 Stumpjumper Comp 29) for 1 1/2 seasons. Other than putting some nifty grips on it and some knobbier tires, it's all as it came from the from the factory.

This year was my first season of racing (Sport class). I weigh 125 lbs. I've never had a pinch flat. I have had 2 punctures this year (same trail, different days). I usually run 24-26 psi. A certain trail is easier at 22-23 psi. Often, I just squeeze my tires, decide "good enough," and go ride. I like The Captain Control tires.

Husband does most of my bike maintenance (but the local shop does stuff that needs a tool he doesn't have and things he doesn't have time to do). He expects me to do more and more of my own bike work. That would include going tubeless since he has no interest in fussing with it.

I already know I'm converting from 3 X 10 to 1 X 10. I'm looking for other ways to lighten the bike. Right now it is 25 lbs. Guy at the shop is recommending new wheels.

The thing that put me over the top to convert to tubeless was getting a flat in a race that tubeless would have prevented. That's 95% of the reason I switched. In switching, I recognized the benefits of running a lower pressure than possible with tubes. The efficiency and performance gain was minimal.

You will likely not get a noticeable performance gain from losing the .25 lbs you will typically get from switching to tubeless. If you are buying a new set of wheels, you're looking at $750+ all in for anything that will give a noticeable gain. Is it worth it?

How much faster do you believe a set of wheels and tubeless tires will enable you to be? 1 minute per 10 miles? 2 minutes per 10 miles? 5 minutes per 10 miles?

You'd be amazed at how little gain it actually gets you. If you're racing, then it matters. If you're not, then it doesn't.

No, YOU don't understand. You're making an ass of yourself for all of eternity.

006_007, your test sounds scientific enough to me. You confirm my belief that it is unlikely that rolling resistance due to tire/tube interaction is significant or occurs at all. BUT, if you tried the same test at say 30 back /25 front PSI with tubes and 25/20 without, over some roots and other uneven trail surfaces, I would expect to see an improvment. The tire conforms to the trail surface rather than bouncing over it. There is a whitepaper by Schwalbe where they tested this, and my seat-of-the-pants experience agrees. I also believe that the tires get better traction. It is definately more comfortable!
.

I dunno, my experience is that less tire pressure means the tire is going to conform to irregularities on the trail more meaning more surface area contacting which equals more resistance........

It may feel more stable and provide more traction though - but more traction is an INCREASE in resistance no?

Increased traction doesn't necessarily mean increased rolling resistance. Traction stops the tire from slipping, but rolling is a different thing.

When going over irregularities, a tire without a tube will conform to the changes more easily, so it's more noticeable than on hard and smooth surface.

006_007, my observation could be placebo, because if the effect was as big as I perceive, it should be easily replicated in an empirical test. However, I think if you rolled as far with a tubeless setup - which is lighter and thus has less freewheeling effect - you already witnessed a lower rolling resistance. (Whether this can be noticed when riding is a different thing entirely.)

Increased traction doesn't necessarily mean increased rolling resistance. Traction stops the tire from slipping, but rolling is a different thing.

When going over irregularities, a tire without a tube will conform to the changes more easily, so it's more noticeable than on hard and smooth surface.

006_007, my observation could be placebo, because if the effect was as big as I perceive, it should be easily replicated in an empirical test. However, I think if you rolled as far with a tubeless setup - which is lighter and thus has less freewheeling effect - you already witnessed a lower rolling resistance. (Whether this can be noticed when riding is a different thing entirely.)

Traction and rolling resistance are different, though not exclusive. A smooth tire at 60 psi will roll better and have less perceived "resistance" than a smooth tire at 30 psi. Add in an actual tread pattern, trail surface irregularities, and fluctuations in rider weight and strange things start to happen. A softer tire will have more rolling resistance, since there is more tire material in contact with the ground. This will occur with or without tubes. You will also gain traction, as there is a larger contact patch. However, a different tread pattern may offer more traction at a given psi without impacting rolling resistance.

Hence a difference between 2" tires and 2.3" tires

I looked into tire mechanics a while back, and you would not believe how much science and engineering is behind upper-end tread patterns...they are not just the marketing department saying "looks cool to me"...there's work put into the design.

Karidne, I spent about $50 going tubeless. You can subtract from that $10 because otherwise I would have had to buy a spare 29" tube. The difference in how it rides is small. If it were just a matter of weight savings, even on the wheels, is it worth $50? For recreational riding, no. For racing or if you just enjoy going fast, probably. I did one race last year for bangs, enjoyed it, and plan to do three this summer. Seeing you are more into racing than I am, depending on your financial sitution, it would probably be a good thing for you. As things go, $50 isn't a huge amount of money to spend in this sport.

That's assuming you can do it for $50 on your bike. I don't know anything about Specialized or your bike other than that they are very popular around here

One thing, though. If you go tubeless, you don't want to have to rely on the LBS to maintain your setup. You need to know how to mount tubeless yourself. So do the conversion yourself. It isn't difficult. Getting the bead to seat enough to hold air using a hand pump is a bit of a black art at first, but not difficult after you do it once. I keep a Schrader adapter in my toolbox so I can use a compressor if I ever need to or am just lazy.

As for new wheels, I am a relative noob, but let me share this. My old bike is a steel '98 Schwinn Mesa weighing in at around 30 lbs. I brought it at a thrift store. It still had its factory tires. I replaced them with tires from the LBS and saved 11 oz per wheel! It rode like a different bike. Pedaled easier, accelerated and stopped easier, handled better, was more responsive. A HUGE difference.

A guy at the race had the same bike I had, a Superfly AL elite, but his had I9 wheels. He let me ride it around the start/finish area, and it was NICE. I'll bet the difference on the trail is substantial. So I plan to spend the $$$ I didn't spend on a carbon frame and get some really nice wheels sometime . You benefit from more than just weight savings, you know. A good wheelset will be stiffer and the hub will have more engagament points. Also look into thru-bolt if you don't already have thru-axle.

It may feel more stable and provide more traction though - but more traction is an INCREASE in resistance no?

Actually, the opposite is true, at least if we look at overall efficiency. Consider this extreme example:. You are pedaling up a hill, but the back tire is spinning and you are not moving at all. You are getting 0% efficiency. All of your energy is going into warming up the environment and tearing up the trail . You get a wider tire or let some air out of yours, and it now climbs the hill. You are no longer at 0% efficiency -- you are infinately better off! So in reality, the less slipping and sliding you do, the less work you do.

The Schwalbe paper I mentioned a couple of posts ago claims that additional rubber on the road does not add to rolling resistance. The reason to go with narrow tires on a road bike is weight savings, but mostly lower wind resistance. It sounds like heresy based on everything I have read and been told with respect to cars, but just thinking about it logically, I see no reason why road molecules and tire molecules merely touching each other is going to generate heat.

The Schwalbe paper I mentioned a couple of posts ago claims that additional rubber on the road does not add to rolling resistance. The reason to go with narrow tires on a road bike is weight savings, but mostly lower wind resistance. It sounds like heresy based on everything I have read and been told with respect to cars, but just thinking about it logically, I see no reason why road molecules and tire molecules merely touching each other is going to generate heat.

I know, its seems counter intuitive to think lowering tire pressure doesn't slow you down. I get the increased traction, larger contact patch, but everything I ever heard says higher pressures equal less resistance. I guess I'm just going to have to try it.

Ok, not really. The main purpose is flat prevention and the ability to run lower pressures w/o pinch flatting. If you are have tubeless-ready rims/tires, it will be a bit lighter than a tubed set-up. If you convert with a rim strip, it will be marginal in terms of weight reduction.

It may be the wrong choice of words to choose to describe the speed in which you travel with high pressure vs low pressure. If you are on pavement or smooth, hard packed dirt, higher pressure will require less energy to cover the same distance when compared to lower pressure. If you are on a surface with a lot of bumps, lower pressure will require less energy to cover the same distance compared to higher pressure.

Think of it this way. The shortest distance between two points is a straight line. A straight line is the most efficient path between two points.

Now, picture a bike from a side view and imagine a chart of the Axels' paths while riding a smooth road at 60 psi. In that scenario, higher pressure or lower pressure results in a straight line. Now, imagine putting a bunch of roots and rocks along that path and chart your axles' paths with 60 psi and also 25 psi. the 60 psi path will look like a heart beat monitor and the low pressure will look like a sound wave. Every time you change your axles' paths abruptly, you are loosing energy/efficiency.

If you have 100% energy devoted to moving the bicycle forward, any movement in any direction other than forward reduces your energy devoted to moving forward and converts it to energy in a different direction. It's the same reason we use suspension. It's all about energy efficiency.

There is a point of diminishing returns. It's all about trade-offs. That's why no one answer is best in every situation.

No, YOU don't understand. You're making an ass of yourself for all of eternity.

I have a dolly that i use to move stuff with. Usually, with the tires aired up, i strap something on it and push it along. Not much effort. The other day, the tires were lower than normal and squished about 1/4-1/2 its total sidewall height with the same thing on it. It took a bit of effort to roll this around. I doubt it was due to the added tread on the pavement. Probably more the "flattening" of the contact point. But, lower pressure does add to rolling resistance.

I'm sure that low pressures (big reason to go tubeless) has its traction benefits. But, there must be a rolling resistance added by doing it. Is this resistance noticed on a rocky trail while ascending or descending? I don't know. Does the resistance outweigh the traction benefits? Everyone has to make that decision for themselves.

I have a dolly that i use to move stuff with. Usually, with the tires aired up, i strap something on it and push it along. Not much effort. The other day, the tires were lower than normal and squished about 1/4-1/2 its total sidewall height with the same thing on it. It took a bit of effort to roll this around. I doubt it was due to the added tread on the pavement. Probably more the "flattening" of the contact point. But, lower pressure does add to rolling resistance.

I'm sure that low pressures (big reason to go tubeless) has its traction benefits. But, there must be a rolling resistance added by doing it. Is this resistance noticed on a rocky trail while ascending or descending? I don't know. Does the resistance outweigh the traction benefits? Everyone has to make that decision for themselves.

This is not accurate for bicycle tires. Do not assume that lower air pressure results in higher rolling resistance. That is ancient thinking. Roadies used to believe that a tire with 120 psi would have less rolling resistance than a tire at 100 psi. This has been proven to be wrong.

A roadie (135lb lightweight) on rock hard tires at 120psi or rock hard tires at 100psi? Neither are going to deform (flatten) the contact patch with pressures that high with so little volume. Air up that road tire to 50psi and there will be a difference in rolling resistance. If there wasn't, they would only use 50psi. Mountain bike tires have much more volume and are used at much lower pressure. A "flatter" tire is going to roll slower. Mountain bike, car, trailer, dolly, hula hoop, and even a roadie tire. I can feel the difference with my legs between a 45psi tire and a 30psi tire.

This is not accurate for bicycle tires. Do not assume that lower air pressure results in higher rolling resistance. That is ancient thinking. Roadies used to believe that a tire with 120 psi would have less rolling resistance than a tire at 100 psi. This has been proven to be wrong.

Lower pressure does not add to rolling resistance.

On a road bike, you gain some speed by this small drop in pressure because the bike is not bouncing "over" every single surface irregularity, much like how a suspended bike is faster over rough terrain that a fully stiff frame.

On a mountain bike, a drop in air pressure after a certain point will increase your rolling resistance, and the amount of work required to move the bike a certain distance. The key is finding a tire's "butter zone", or the point at which the tire is most efficient in passing over the majority of surface irregularities (like the average size of gravel on a trail). The trail type matters, too (DH rock garden vs. flowing singletrack).

However, there are exceptions. As I found out from experience and a following thread post on this website, a tire with tall, knobby tread, when inflated to a high psi, will squirm around more than at a lower psi, and therefore have more rolling resistance at high psi's than at lower psi's (I had WTB mutanoraptors inflated to 45-50 psi while riding on wet concrete...almost killed me). Squirming is a loss in tire efficiency.

Jetboy's on the right track with this...though again, you do gain some speed in not bumping over every grain of sand (drop from 120 to 100 gives you this little bit of cushion).

On a road bike, you gain some speed by this small drop in pressure because the bike is not bouncing "over" every single surface irregularity, much like how a suspended bike is faster over rough terrain that a fully stiff frame.

On a mountain bike, a drop in air pressure after a certain point will increase your rolling resistance, and the amount of work required to move the bike a certain distance. The key is finding a tire's "butter zone", or the point at which the tire is most efficient in passing over the majority of surface irregularities (like the average size of gravel on a trail). The trail type matters, too (DH rock garden vs. flowing singletrack).

However, there are exceptions. As I found out from experience and a following thread post on this website, a tire with tall, knobby tread, when inflated to a high psi, will squirm around more than at a lower psi, and therefore have more rolling resistance at high psi's than at lower psi's (I had WTB mutanoraptors inflated to 45-50 psi while riding on wet concrete...almost killed me). Squirming is a loss in tire efficiency.

Jetboy's on the right track with this...though again, you do gain some speed in not bumping over every grain of sand (drop from 120 to 100 gives you this little bit of cushion).

Again, finding the "butter zone" for a specific tire is key.

Good. The fallacy is that some people believe that higher pressures always result in less rolling resistance. The actual results are what matter. Tire width plays a part in this. A 20mm wide tire at very high pressure has to deform the same amount as a 25mm tire at lower pressure. The shape of the contact patch is different. The 20mm casing has to deform over a longer distance to support the riders weight, so it has a larger deflection amount than the 25mm wide tire.

Riding on rock-hard tires feels efficient, but that is just a feeling.

They told me bathing in boiling water would be fatal, so I dropped the temperature below zero and it froze. I still didn't get the bath.

That's what I think when I read stuff about lower pressures increasing rolling resistance. Well of course the rolling resistance will be higher, if you're riding flattened 2.35 mm mud tires on smooth pavement. What happens on the trail is vastly different.

They told me bathing in boiling water would be fatal, so I dropped the temperature below zero and it froze. I still didn't get the bath.

That's what I think when I read stuff about lower pressures increasing rolling resistance. Well of course the rolling resistance will be higher, if you're riding flattened 2.35 mm mud tires on smooth pavement. What happens on the trail is vastly different.

A flat tire on or off road does increase rolling resistance. I guarantee it.

A flattened mud tire may be faster at getting through mud than a pumped up tire, but it still has more rolling resistance than when inflated to its "Goldilocks" psi.

CSC, you are right. Rolling resistance is rolling resistance. The terrain doesn't magically change the rolling resistance physics. Running lower pressure is higher rolling resistance regardless of the terrain. The same bike with the same rider with the same tires is going to have lower rolling resistance at 40 psi vs 25 psi regardless of terrain. The difference is the energy expended to make it from point a to point b on various terrain with 40 psi vs 25 psi. Running lower tire pressures is an argument of efficiency, not rolling resistance. The reason this is relevant is because you can run lower pressures, when necessary, with a tubeless setup compared to a tubed set up. Running lower pressures is not more efficient on every trail.

No, YOU don't understand. You're making an ass of yourself for all of eternity.

You could in theory run them flat (no air...) on a smooth surface...assuming you did not cut the wall of the tube with your rim or something on the ground.

In practice, you would have to have enough air to press and hold the tire bead to the rim...in the neighborhood of 15-20 psi, to be safe. I have ridden on less than 20 psi...not great, but possible. Tubeless allows you to glue the bead to the rim, so you might get lower psi on the tubeless set-up, but things would start getting sketchy.

EDIT: I mean, no one would run 15 psi tubeless, right?

The whole issue is how low can you go and not have the tire pop off the rim or compress and get lacerated by the rim? Tubeless gives you a bit more flexibility.

I'm looking for ways to make my bike lighter, will going tubeless help?

Some details, if you want them:

I've been riding this bike (2011 Stumpjumper Comp 29) for 1 1/2 seasons. Other than putting some nifty grips on it and some knobbier tires, it's all as it came from the from the factory.

This year was my first season of racing (Sport class). I weigh 125 lbs. I've never had a pinch flat. I have had 2 punctures this year (same trail, different days). I usually run 24-26 psi. A certain trail is easier at 22-23 psi. Often, I just squeeze my tires, decide "good enough," and go ride. I like The Captain Control tires.

Husband does most of my bike maintenance (but the local shop does stuff that needs a tool he doesn't have and things he doesn't have time to do). He expects me to do more and more of my own bike work. That would include going tubeless since he has no interest in fussing with it.

I already know I'm converting from 3 X 10 to 1 X 10. I'm looking for other ways to lighten the bike. Right now it is 25 lbs. Guy at the shop is recommending new wheels.

Check your rims first. My 2012 SJ FSR Comp 29 came taped stock so all I had to do was buy valves and sealant.

Depends on your weight, riding style, terrain type, tube type and tire type. I experiment and run different psi on different trails in different conditions.

On pavement or hard packed, smooth, single track, I run max psi according to sidewall. A lot of people recommend running as low psi as possible. Not sure I recommend that for every trail unless your goal is to have the most traction and the most comfortable ride possible. You can find out your minimum PSI by going to the roughest section of the trail and doing multiple passes and lowering the pressure by 2 psi each pass until you can feel your rim very lightly "kiss" a rock/root. If there are any rocky downhill sections, use that as your experimentation run. If you don't pinch flat, raise the psi by 1 and that should be your minimum.

No, YOU don't understand. You're making an ass of yourself for all of eternity.

I can't believe all the back and forth about rolling resistance and the theory of it. Stop reading this crap, convert them to tubeless, run lower pressure than your are used to, and go for a ride. Then you can make your own opinion of whether or not you think it works. This reminds of me of all the theorizing that goes on about 29ers, whether they roll over things easier, whether they climb easier, whether they are faster, blah blah blah. Just buy one and ride it. If you like it, great, if you don't, sell it and go back to your 26er.

I can't believe all the back and forth about rolling resistance and the theory of it. Stop reading this crap, convert them to tubeless, run lower pressure than your are used to, and go for a ride. Then you can make your own opinion of whether or not you think it works. This reminds of me of all the theorizing that goes on about 29ers, whether they roll over things easier, whether they climb easier, whether they are faster, blah blah blah. Just buy one and ride it. If you like it, great, if you don't, sell it and go back to your 26er.

you're already going from 8speed to 10speed for reasons that make sense only to you. why ask us about tubeless?

sounds like you are a guy with some money to spend who likes to have nice stuff, even if he doesn't necessarily know why. all the guys like you have tubeless. all of them say it is way superior to tubes, even though they can't exactly explain why.

it sounds like other people do all the work on your bike, so that is something in favor of getting tubeless - if you don't have to do the work yourself and have the money, why not get it?

i hope it doesn't sound like i'm raining on your parade. i guess i'm just saying that only you can decide, and a lot of guys like you have gone to tubeless. whichever way you go, i hope you are happy and get to ride it plenty.

I'm going from 8 to 10 because I got a screaming deal on parts. And actually I did all the upgrades myself.

After reading all the feedback, I'm thinking just sticking my my current setup and run tubes. The extra money for a tubeless set up doesn't seam to make since. Thanks for all the feedback guys!

Increased traction doesn't necessarily mean increased rolling resistance. Traction stops the tire from slipping, but rolling is a different thing.

When going over irregularities, a tire without a tube will conform to the changes more easily, so it's more noticeable than on hard and smooth surface.

006_007, my observation could be placebo, because if the effect was as big as I perceive, it should be easily replicated in an empirical test. However, I think if you rolled as far with a tubeless setup - which is lighter and thus has less freewheeling effect - you already witnessed a lower rolling resistance. (Whether this can be noticed when riding is a different thing entirely.)

I found that indeed I had more traction and less rolling resistance at the same time. I no longer slip on the same gravel road climb that I used to w/ tubes when standing and pumping he pedals hard. Likewise I have seen like 1 - 1.5 MPH faster rolling speed on a couple of test rides on the same roads. I can feel it is easier to pedal for the same speed on pavement and this is with running 28psi tubeless compared to 35-40 w/ tubes. I had been running a pretty heavy tube in the tires. And this is with the exact same tires tubes and tubeless.

Hardest thing I have found so far is fighting that old urge to "pump those tires up", I am used to 50-70psi in my touring bike and 90-100psi on my road bike.

I found that indeed I had more traction and less rolling resistance at the same time. I no longer slip on the same gravel road climb that I used to w/ tubes when standing and pumping he pedals hard. Likewise I have seen like 1 - 1.5 MPH faster rolling speed on a couple of test rides on the same roads. I can feel it is easier to pedal for the same speed on pavement and this is with running 28psi tubeless compared to 35-40 w/ tubes. I had been running a pretty heavy tube in the tires.

Hardest thing I have found so far is fighting that old urge to "pump those tires up", I am used to 50-70psi in my touring bike and 90-100psi on my road bike.

Not relevant data unless you used the same tires. Lighter tires with a new tread pattern with no tubes, and a bit of the good old placebo effect will do wonders for climbs.

And wmac...I deemed the conversation closed, as the OP made a choice (as it turns out my comment was correct...I just thought it was a little useless to have it up after OP said effectively the same thing).

A flat tire on or off road does increase rolling resistance. I guarantee it.

Of course it does. I don't think anyone in this thread disagrees.

Originally Posted by CSC

A flattened mud tire may be faster at getting through mud than a pumped up tire, but it still has more rolling resistance than when inflated to its "Goldilocks" psi.

Well, "flattened" is a relative term. If by "Goldilocks" you mean optimum pressure, then I agree - and it will be faster too.

Originally Posted by wmac

CSC, you are right. Rolling resistance is rolling resistance. The terrain doesn't magically change the rolling resistance physics. Running lower pressure is higher rolling resistance regardless of the terrain. The same bike with the same rider with the same tires is going to have lower rolling resistance at 40 psi vs 25 psi regardless of terrain. The difference is the energy expended to make it from point a to point b on various terrain with 40 psi vs 25 psi. Running lower tire pressures is an argument of efficiency, not rolling resistance.

As someone who rides on streets and roads and off-road trails, I could not disagree more strongly. Rolling resistance happens between the tire and surface, and both of these have an equal part in the whole equation.

If we push a bike on a smooth polished surface, maybe glass, we'll indeed get the lowest resistance with the tire pumped as hard as it can take.
Step out to the real world to as much as pavement, and you'll notice vibration with the bike set up for a glass surface. Reduce the pressure a bit to make the tire conform to the irregularities and the rolling resistance will be reduced as well.
Asphalt in a bad condition requires again a slight drop in pressure to optimize rolling resistance.
When riding on a trail with rocks, roots and other bumps, lowering the pressure even further will reduce rolling resistance.

Of course one could ask the question "lower than what?", and it's a good question. The "lower your pressures for rougher conditions" is not a suggestion to go below the optimum pressure, but find the optimum one. Higher for harder and smoother surfaces, lower for bumpier and softer conditions.

Originally Posted by CSC

I mean, no one would run 15 psi tubeless, right?

Been there, done that. It increased the rolling resistance a bit, while traction only got better. Depends on a few things - I weigh 72 kg (158 pounds) and have 21 mm (inside width) rims with 2.35 29er tires.

Do note that I'm not saying people should run lower pressures, but instead find the right one for their weight, tires, trail and riding style. In some cases lowering the pressure will reduce rolling resistance, but going too far will make it increase again.

The same bike with the same rider with the same tires is going to have lower rolling resistance at 40 psi vs 25 psi regardless of terrain. The difference is the energy expended to make it from point a to point b on various terrain with 40 psi vs 25 psi. Running lower tire pressures is an argument of efficiency, not rolling resistance.

this is what matters... rolling resistance is often used in the same sentence with average speed and traction.

lower pressure tires may have higher rolling resistance (dependent on the design and thread - in some cases the difference is INSIGNIFICANT) but in most cases - off road - lower resistance means higher average speed OR less energy required to cover the distance between point A and point B.

lower pressure tires better conform to the rough nature of off road trails where the rubber requires less energy to absorb the roughness as opposed to the rest of the bike - suspension, frame, seat post, handlebar etc...

always added benefit is traction - which increases with softer tires.

about the only negative side is messy setup (non ust) and often tire changes - which i addressed by owning 2-3 sets of wheels - to address different riding/racing conditions (mostly racing). if you do not change tires often - this negative side may be easily ignored.

Well, "flattened" is a relative term. If by "Goldilocks" you mean optimum pressure, then I agree - and it will be faster too.

Of course one could ask the question "lower than what?", and it's a good question. The "lower your pressures for rougher conditions" is not a suggestion to go below the optimum pressure, but find the optimum one. Higher for harder and smoother surfaces, lower for bumpier and softer conditions.

Do note that I'm not saying people should run lower pressures, but instead find the right one for their weight, tires, trail and riding style. In some cases lowering the pressure will reduce rolling resistance, but going too far will make it increase again.

Which is why I keep referencing the tire's "butter" or "Goldilocks" psi zone. We are arguing about saying the same thing. Look over my posts if you disagree.

conforms to trail surface

Tubes hold the tire round at the bottom.
Tubless allows it to conform to the surface giving you wonderful grip.
As for rolling resistance....dont run super low pressures.
I run a 29er 2.35 with tube 32psi in rocky north jersey.
I switched to tubless and run 28-30 psi. Ride wt 200lbs
Incredible grip performance.......
When i run below 28 it feels sluggish.
At 28-30psi i have never flatted, burped or had trouble mounting them for an entire season.
I have even run none ust tires on none ust rims.....if they snap into the bead then it is a good candidate for tubless.......stans tape & fluid.
Go tubless for traction.
I only read a few posts that hit on traction.....but this seems to be the reason that i think you should switch.
For me it was not weight or supper low pressures.
After a season on them switching back to tubes does not feel as confident on tricky terrain.

CSC, seems that there was a bit of miscommunication and semantic differences at play. I also think we agree on almost everything with regards to tire pressure.

Just one thing I call to question, and it's the assertion that higher pressure always means lower rolling resistance. In my opinion it is only true on a perfectly smooth surface: tire deflection is a major contributor in that case. However, if you ride a rock hard tire on asphalt that has seen its better days, the rough surface under the hard tire will result in a higher rolling resistance, while the same tire with a bit less pressure allows the tire to soak up the bumps.

In short, I acknowledge that dropping the pressure too low will increase rolling resistance. Quite often tires roll better with a bit higher pressures than lower, but there is also an upper limit, a point where increasing pressure ceases to reduce rolling resistance.

Rolling Resistance and Tire Pressure"Wider 28-mm tires are as fast at 85 psi as they are at higher pressures."
"At 130 psi (9 bar), the narrow Clement Criterium rolled slower than it did at a more comfortable 105 psi. The wider Clement Campione del Mundo rolled slightly faster at 85 psi than at 105 psi."

1. This study was conducted using road tires.
2. This is interesting: "Riding your tires at the “optimum” pressure optimizes both comfort and performance. At lower pressures, you roll slower. At higher pressures your bike is no faster, but much less comfortable. Our tests of the same tires at various pressures determined the
optimum pressure for each tire for our rider/bike combination." Duh. The question is, how to determine optimum tire pressure for MYB tires. They suggest a method, but not sure if it pertains to MTB tires.
3. I did not find anything in that study that contradicted anything I've written in this thread.

I'm beginning to agree with you guys, WTF are we arguing about?

Why tubeless? Reduce/eliminate flats and have wider range of tire pressure adjustment in order to find "optimum" tire pressure for trail, rider and style.

No, YOU don't understand. You're making an ass of yourself for all of eternity.

CSC, seems that there was a bit of miscommunication and semantic differences at play. I also think we agree on almost everything with regards to tire pressure.

Just one thing I call to question, and it's the assertion that higher pressure always means lower rolling resistance. In my opinion it is only true on a perfectly smooth surface: tire deflection is a major contributor in that case. However, if you ride a rock hard tire on asphalt that has seen its better days, the rough surface under the hard tire will result in a higher rolling resistance, while the same tire with a bit less pressure allows the tire to soak up the bumps.

In short, I acknowledge that dropping the pressure too low will increase rolling resistance. Quite often tires roll better with a bit higher pressures than lower, but there is also an upper limit, a point where increasing pressure ceases to reduce rolling resistance.

Yes. The "butter zone" takes into account the upper and lower bounds of optimal tire pressure for a given tire.
A rock hard tire will ride over every single bump, effectively forcing the bike to travel a further distance than if the tire rolls "through" bumps. Think about tens of bumps, each causing millimeter rise and fall in the bike every second...over 20 miles, this will add up to quite a bit of extra distance traveled...hence the advantage of knowing the optimal tire pressure for a given tire, which will reduce this seemingly trivial but incredibly wasteful up-and-down motion of the bike...which also tires out the rider, by the way.

1. Yes. The info from Schwalbe (who you quoted earlier) is also about road tires: Inflation Pressure | Schwalbe North America"The following applies for the road: The higher the inflation pressure the lower the rolling resistance of the tire."

I think most (if not all) principles can be applied for MTB tires as well: slick is faster, hard is faster - up to a point where you don't gain advantage and start reducing performance.

A quote from wmac earlier in this thread: "If you are on a surface with a lot of bumps, lower pressure will require less energy to cover the same distance compared to higher pressure."

This is precisely what I'm also trying to get across. It seems I call this reduced rolling resistance, you call it improved efficiency, for CSC it's something achieved by a "butter zone" pressure. We agree on the practical side, but differ in semantics. I'm happy with that.

As for a method to find the right MTB tire pressure for yourself, I suggest the following:

1) If you only ride for your own amusement, try out different pressures and use what feels best.
2) If you race, time your laps on an actual trail to see which pressure allows you to ride fastest.

just an additional thought

i truly believe that using a tire pressure with in the range of the recommended pressure listed on the tire is crucial. The side wall is designed to hold strong between those pressures and support the volume of the tire under the rim. Below it and the side wall will collapse and roll out from under the rim causing a wash out. Especially true on a tubeless when there is no tube to help the tire's side wall from folding. The upper limit is more for rim/bead interaction.

In the Beginning…

Tubeless officially debuted for mountain bikes in 1999. Mavic, Michelin, and Hutchinson worked together to create a new standard for mountain wheels and tires called Universal System Tubeless, or UST. Under this new standard, the tire’s casing is thicker all the way around – essentially transferring the weight and material of an inner tube on to the tire itself.

You need the proper inflation to support the volume of air and keep it under the rim.

Saul: Agree, agree, agree. I think the point I was trying to make was that having a higher rolling resistance (lower pressure than butter zone) is a good strategy because many trails have drastically differing terrains and you have to make trade offs based on what is going to net you the greatest efficiency. So, a course that is mostly flat, hard packed with little variation may be best. Change that course to very technical rocky sections that require high traction and grip and you may be better off with lower pressure. Hence, ride the highest pressure possible while maintaining optimal traction in the most difficult sections - just like you also mentioned

No, YOU don't understand. You're making an ass of yourself for all of eternity.

I think we went a bit off-topic with the tubeless thing when one benefit of tubeless was said to be the ability to run lower pressures. From there it went to pressures without regards to tube vs. tubeless.

We overlooked the fact that the comparison wasn't between the same setup with a higher and lower pressure, but rather "with a tube, higher pressure" and "tubeless, lower pressure".

I would argue that removing the tube has a positive effect on rolling resistance, which may be negated by lower pressure, so one hypothetic outcome would be "less pressure, same rolling resistance". I.E. when you go tubeless, you can run lower pressures for the traction and smooth ride without increasing rolling resistance compared to your old setup with tubes.

Great point Saul! For those lurking noobs - the reason this is the case is because it takes energy to deform a pressurized tire and tube. It takes energy to pinch a tire and tube, right? Same thing is constantly happening when you are riding. As you ride, the tire and tube has to constantly change from round to flat to round as it passes over the contact patch. When you eliminate the tube, you energy the loss that happens when the tube goes through that cycle.

So, it's true when converting the same tire with and without tubes. It might not be the case if you go from a standard tire with tubes to a UST tire because of the stiffness of the sidewall, etc. This is why lighter tires often have lower rolling resistance- because it takes less energy for the casing to go from round to flat to negative arc (for roots and rocks) and back to round.

This principle also explains why it is more difficult to push that dolly with low pressure tires compared to higher pressure. But, put a stick in front of that Dolly's tires and the force that is required to push the dolly over the stick is lower with lower pressure tires compared to higher pressure tires. The "butter zone" is to minimize the force required to move over smooth and irregular surfaces.

No, YOU don't understand. You're making an ass of yourself for all of eternity.

Great point Saul! For those lurking noobs - the reason this is the case is because it takes energy to deform a pressurized tire and tube. It takes energy to pinch a tire and tube, right? Same thing is constantly happening when you are riding. As you ride, the tire and tube has to constantly change from round to flat to round as it passes over the contact patch. When you eliminate the tube, you energy the loss that happens when the tube goes through that cycle.

So, it's true when converting the same tire with and without tubes. It might not be the case if you go from a standard tire with tubes to a UST tire because of the stiffness of the sidewall, etc. This is why lighter tires often have lower rolling resistance- because it takes less energy for the casing to go from round to flat to negative arc (for roots and rocks) and back to round.

This principle also explains why it is more difficult to push that dolly with low pressure tires compared to higher pressure. But, put a stick in front of that Dolly's tires and the force that is required to push the dolly over the stick is lower with lower pressure tires compared to higher pressure tires. The "butter zone" is to minimize the force required to move over smooth and irregular surfaces.

This principle also explains why it is more difficult to push that dolly with low pressure tires compared to higher pressure. But, put a stick in front of that Dolly's tires and the force that is required to push the dolly over the stick is lower with lower pressure tires compared to higher pressure tires. The "butter zone" is to minimize the force required to move over smooth and irregular surfaces.

Though again, deflate those tires too much, and you again start increasing the effort required to overcome the "stick" due to all the extra tire deformation going on. Not too hard, to too soft, just right.

Boy was it ever Worth converting...Sorry I waited so long.

Well after posting here about converting to tubeless, I took the bike for spin on Thursday out in the desert and I ran threw a thorn patch where I picked up 4 punctures in the rear & 6 in the front tire. If I had been on tubes i would have had to change the tube on the front and use 1 patch kit to fix up the rear. Otherwise I would have had to walk up to the trail to a road and call for a ride. Went for a another 10 mile ride today, I never aired up the tires since they were as firm now as 4 days ago.

Ok Ill start by saying yes Im a noob and may not have a valid opinion as I have never run tubeless but noone here has mentioned rotational mass.If you run circus wheels and you save weight in the tyre you dont just save on rolling resistance(or not) but the rotational mass will be much less, meaning that pedaling will be easier and the bike will have less momentum. Maybe it would make a 29er pedal a little more like a 26"

Ok Ill start by saying yes Im a noob and may not have a valid opinion as I have never run tubeless but noone here has mentioned rotational mass.If you run circus wheels and you save weight in the tyre you dont just save on rolling resistance(or not) but the rotational mass will be much less, meaning that pedaling will be easier and the bike will have less momentum. Maybe it would make a 29er pedal a little more like a 26"

The weight reduction doesn't make pedaling in itself easier, but acceleration and climbing benefit from reduced weight.

As for a 29er pedaling like a 26... There's way more to that. I've run my 29er with tubes before going tubeless and my 26" also tubed and tubeless. None of the four setups compare to each other. The size difference makes way more of a difference than tubes vs. tubeless.

I'll just say tubeless offers several benefits no matter what size tires you like to run. Even my road bike is tubeless.

what kinda upkeep do you have with tubeless? how long before the sealant loses it stick, does it dry out and lose it integrity inside the tire over time. Do you need to add more sealant ever few rides?.

I keep thinking about switching because most of my tubes are more patch then tube, im 250ish in full kit 240 for my average ride. But its rough rooty and rocky and im not the best rider int he world so i miss alot of kicks and case stuff all the time ending in lots of pinch flats.

The tubeless system seems a great idea, but it also seems like it could be a bit of a pain int he ass. Get a flat ont he side of the trail and now you have tubeless goo to deal with aswell as allt he mud and dirt.. i dunno

what kinda upkeep do you have with tubeless? how long before the sealant loses it stick, does it dry out and lose it integrity inside the tire over time. Do you need to add more sealant ever few rides?.

I keep thinking about switching because most of my tubes are more patch then tube, im 250ish in full kit 240 for my average ride. But its rough rooty and rocky and im not the best rider int he world so i miss alot of kicks and case stuff all the time ending in lots of pinch flats.

The tubeless system seems a great idea, but it also seems like it could be a bit of a pain int he ass. Get a flat ont he side of the trail and now you have tubeless goo to deal with aswell as allt he mud and dirt.. i dunno

Change it out every 3-6 months. If you cut a tire on the trail, the sealant likely spewed out already trying to seal it. It has to be a very big cut for this to happen. Just clean the area and put a patch on the tire and put a tube in like you would with a normal flat.

No, YOU don't understand. You're making an ass of yourself for all of eternity.

how is the DT swiss tubeless conversion kits compared to stans? the price is a little bit better and i would imagine things would be better fitted for the rims i have. Is tubeless brew pretty much the same through everyone?

Someone (I know who you are ) gave me negative rep for my first post to this thread, and I want to comment.

cars with tubeless tires get better gas mileage? compared to all the cars out there with tubes? nice try

My point exactly. That's one reason why tubed auto tires are a thing of the past thankfully.

I have probably been around a little longer than the commentor. While tubeless tires were pretty much standard even when I was a child, there was still a discussion of tubes vs tubeless for cars, and there were a few old-timers who liked tubes. I remember my high school auto shop teacher discussing the advantages of tubeless, and he mentioned cooler running and better gas mileage. (Radials have the same advantages BTW).

Anyway, give it another 10 years, and I will surprised if tubes aren't pretty much a thing of the past in better-than-department-store bikes. If'm I'm wrong, you can give me more negative rep. And, the people who think they roll noticibly easier, while I don't agree, have some evidence to back them up.

Anyway, give it another 10 years, and I will surprised if tubes aren't prettymuch a thing of the past in better-than-department-store bikes. If'm I'm wrong, you can give me more negative rep. And, the people who think they roll noticibly easier, while I don't agree, have some evidence to back them up.

I doubt that. First of all it's a messy thing to do. People don't like to deal with mess.
Second of all: It can get time consuming with all the shaking, and turning and soap water and stuff. You can argue that you can swap tubeless tyres in 15 minutes, but that's your skill with your specific setup.
Third: It's more expensive. Maybe not that much, but for many people that take cycling more as an occasional hobby than a passion it can be a valid factor.

Techniques, tools and components develop. Once technology becomes more common, prices drop. Tubeless will increase in popularity as a result.

That said, tubes will probably remain the easier way and some people can't tell the difference (or the convenience outweighs the slight advantage). As opposed to cars, end users change tires a lot more so ease of installation is a more significant factor.

Not all people (or even enthusiasts) are willing to go that far for some performance. This applies to tubulars as well.

You both make good points. However, I think a lot of the resistance to tubeless is just the momentium that tubes have, like it probably was when tubeless auto tires came out. People often loathe change.

I may be full of it, but I think that once you learn how to deal with tubeless, it is currently as much about convenience as performance -- you can schedule maintenance of your tires at your convenience rather than deal with enroute failures. It doesn't take much to pop the bead and inspect the sealant, adding if necessary. I am trying glycol-based goo. It cleans up with water and is way less messy than Stans. Probably not as good at sealing holes, but from every indication so far, way better than tubes. No failures yet. And no worries about a noob like me pinching a tube while installing it.

Reading here and looking at the healthy number of posters who try a good TLR system and like it and stay with it, and the few that go back to tubes, I'd say it's catching on.

The technology is still in its early stages and there is room for improvment. Imagine if the sealant would last for a year and bikes came from the factory already set up for tubeless. This is not too far-fetched. Heck, there are currently rims that don't need goo. That is a problem if you get a puncture, but if you could plug holes without dismounting like you do your car....